A Relatively Painless Migration to a Futaba TX 8FG

I've been flying a Phantom 1.1.1 (for practice) and a Phantom 2 with a Zenmuse Gimbal and FPV (for filming) since early January, which given the weather here in the NYC area, has been a challenge in itself. I'm a photographer, not an RC enthusiast.

Over the weekend, I migrated both Phantoms to the Futaba 8FG with FASST (a frequency-switching system that is pretty much interference proof.) The process took about four hours and was relatively painless--thanks mainly to a downloadable data file containing complete Naza-M programming for the 8FG (more on that in a moment).

I live in an urban environment. Flying with FPV, I've been increasingly frustrated with the 300m "safe limit" for the DJI transmitter. Knowing that even at 300m there are probably 500 active wi-fi transmitters between me and my Phantom 2 (with about $2,000 of additional goodies aboard) is disconcerting. Obviously, the farther the Phantom, the weaker the signal from the stock DJI TX, and the greater the likelihood of a flyaway.

I've been thinking about the Futaba 8FG with its FASST frequency-switching system that by all accounts is virtually impervious to radio interference.

At first I assumed that in order to switch to the Futaba 8FG, I'd have to replace the RXs in both Phantoms. In the RC Forums I learned that the dual-antenna RX on both my Phantom 1.1.1 and the Phantom 2 are FASST compatible -- meaning that the existing RX can be "bound" to the 8FG (and presumably all of the higher-end Futaba TXs).

Still after watching various You Tube videos on programming a Futaba, it was obvious that setting up a TX from scratch to fly a Naza M V2 was well-beyond my abilities. Which is when I discovered the Aerial Pixels pre-programmed settings file for the 8FG. Cost: $1!

I used the file for the "Naza M / Futaba 8FG" since there's no option for a Naza M V2. It worked just fine! The same Aerial Pixels file worked for the Naza M V2 on both my Phantom 1.1.1 and Phantom 2. No adjustments necessary, except for the slight "Trim" fine-tuning mentioned below which is almost certainly an issue unique to my particular TX.

By following the Aerial Pixels instructions recipe-style, in a few hours I was able to set up the Futaba 8FG for both Phantoms, bind the Futaba TX to the DJI RXs, run the Naza M V2 Assistant apps for both the Phantom 1 and Phantom 2, and take both drones for test flights -- during which everything functioned flawlessly.

The throttle joy stick on the Airplane version of the Futaba 8FG that I bought doesn't automatically center. (For some reason, the "A" version is recommended for multi rotors over the H, or Helicopter version.) But I emailed Futaba service, and two days later, a kit containing a tiny spring, rocker arm and bracket was in my mailbox -- gratis! It took about ten minutes studying the right-hand joy stick to figure out how the return spring works and another ten minutes to install it. Futaba's part number for the return spring kit is 6528769.

There's a good You Tube video demonstrating how to bind a Futaba TX to the Phantom 2's stock RX. It takes about 30 seconds.

Binding the Phantom 1.1.1 is a little trickier, but still only takes a minute or so. It goes like this: turn the TX off, leave the Phantom battery OUTSIDE the battery compartment and connect it. Inside the battery compartment on the underside of the RX board you'll see a red LED. Next to it is a small black button. Hold the button with a screwdriver tip for two seconds. The LED will begin to blink. Turn on the Futaba (be sure to select the YES option that turns on radio transmissions) with your newly uploaded Phantom 1 program selected as the active MODEL, if the blinking red RX LED goes out, you're bound!

Of course, you need to use the Assistant Software to calibrate the joy sticks and make sure all functions -- including IOC, Gimbal, and Fail Safe Return to Home are working properly. The Aerial Pixels program attaches the Gimbal control to one of the 8FG dials, which is a nice touch and makes vertical pans much, much smoother. Also, the RTH Failsafe is programmed to switch "SF," so you can activate Failsafe without turning off the TX. I couldn't see the benefit of this until I realized it takes quite a bit of warmup time and fumbling through menus to actually get the 8FG transmitting.

The only serious hitch I encountered was a -17% error in my throttle at the centered "hover" position on the Phantom 2 (ie. with the throttle centered, the Phantom 2 would slowly descend instead of holding altitude.)

After much fruitless online research, I discovered by trial and error that the little Trim levers next to the joy stick boxes are designed for fine-tuning this kind of problem. I pushed the Trim lever until the throttle arrow centered and turned green in the Assistant app. Problem solved -- or so I thought.

When I went to start up the Phantom, nothing happened. The trouble with adding too much positive trim to the throttle, I discovered, is that the joy stick can no long reach the zero throttle position needed to start and stop the motors. I was, however, able to find a compromise trim position that allows the Phantom to hover without descending -- and still lets me start and stop the motors.

I was willing to fly the Phantom 1 (without a camera) out over Long Island Sound this morning. I'll test the Phantom 2 a little more throughly in the park before heading out on any long FPV "missions." But radio interference aside, the other benefits of the Futaba 8FG I've already discovered are:

1. smoother Gimbal (vertical) pans as well as horizontal (yaw) pans resulting from a much stiffer joy stick that is far easier to control in fine increments.

2. more fluid flights overall thanks to increased control afforded by the high-quality of the Futaba potentiometers. I can now yaw far more slowly and smoothly without also getting unwanted throttle increases and decreases. The same goes for pitch control where I can now go forward, crab, and fly sideways more slowly and smoothly -- and do it without unwanted changes in speed or direction.

3. it will take a few more test flights before I'm comfortable sending the Phantom 2 out over water or on a distant FPV. But when the time comes, I'll surely be far less apprehensive about a random wi-fi network -- or another unseen RC pilot -- seizing control of my Phantom.

But I did the same as you. Watched various videos and managed to get it to work myself.

However there is a profile that Ian Wood has created for the 8FG which has some nice extra features like dual (multi) rate control etc

So its worth looking at.

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Yup. Ian Woods thread is what convinced me to make the upgrade to the T8FGS. His profile works perfect for me! I am also using the stock P2 Rx and found it very easy to bind to the Tx. I start up with full throws to get the motors going then switch to the lowest rate and my P2 flys like butter!

I did take the phantom apart to upgrade it, but I think there would have been issues with the antenna placement as the wires on the Futaba receiver are quite short, so I replaced the stock receiver board (which I started to remove) and then just got bound to the stock receiver.

But I did the same as you. Watched various videos and managed to get it to work myself.

However there is a profile that Ian Wood has created for the 8FG which has some nice extra features like dual (multi) rate control etc

So its worth looking at.

Click to expand...

Hey Roger:

Thanks. That's a great tip! I understand that that DSLR Pros' "fluid pan" is actually just a Dual Rate switch. Sorting out how to set up Dual Rate on the Futaba 8FG is actually the next project on my To Do List.

I did take the phantom apart to upgrade it, but I think there would have been issues with the antenna placement as the wires on the Futaba receiver are quite short, so I replaced the stock receiver board (which I started to remove) and then just got bound to the stock receiver.

Click to expand...

Roger, there's a good You Tube video from Aerial Media Pros (http://www.youtube.com/watch?v=NJ8lkBwu_AY) that covers replacing the RX on the Phantom 2. The key thing is that in order to achieve antenna "diversity" one antenna wire runs down the landing gear just like the stock RX. However, the second antenna get's run across the interior of Phantom shell at a 90 degree angle.

Replacing the RX on a Phantom 1.1.1 looks a bit more intimidating, since the upgraded dual antennae RX has been relocated to a position underneath the main circuit board.

My intention is to eventually replace the Phantom 2 RX with the Furaba R6208SB, but I wanted to be sure to get all the kinks out of the TX end first.

My concern with fitting the Futaba receiver is that although one antenna can be attached to a skid like the original ones, the other antenna would be inside and hence very close to the interference caused by the Naza and the ESCs etc.

I suspect that DJI put both P2 antennas as far away from the internal interference as possible, so I don't want to get worse reception by putting the Futaba antennas in less than than optimal locations.

I have read that some people buy extension antennas from Futaba, but I didn't want to the the Futaba receiver apart and to have to spend $$ on more items to get the P2 flying again.

My concern with fitting the Futaba receiver is that although one antenna can be attached to a skid like the original ones, the other antenna would be inside and hence very close to the interference caused by the Naza and the ESCs etc.

I suspect that DJI put both P2 antennas as far away from the internal interference as possible, so I don't want to get worse reception by putting the Futaba antennas in less than than optimal locations.

I have read that some people buy extension antennas from Futaba, but I didn't want to the the Futaba receiver apart and to have to spend $$ on more items to get the P2 flying again.

So I'm going to try with the stock receiver for a while.

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I've been flying with the stock receiver for a while now. I have yet to get it out far enough to lose the signal. My FPV video drops out before the control signal. That's when I throw it into "return home" and high tail it back. I'm totally happy with the T8FGS and stock receiver set up and see no reason to use the Fuataba Rx. Maybe I'll put it to use on my next quadcopter... the F450.

Those short antennae are only an issue if they are inside a carbon fiber shell or surrounded by carbon fiber- hence the longer antennae on the Futaba Rx in some cases- and as for replacing them, the Futaba Rx is just a board inside a little plastic case that is designed to pop open- those antennae are designed to pop off and be replaced too- it is one of the simplest things to do... so no need or worry about that upgrade or mod.

I will say that all of my research in to the FrSky Rx line of Futaba compatible FASST radios make not using them **** near impossible- they are rating better reception over same or longer distances, and they allow me to use the extra channels on my radio despite the s bus connection- and they are much less money. They also sell antennae individually so you can leave an original one on, and buy a 2 dollar longer one so you can basically match the stock set up in lengths.

I am waiting on a couple in the mail now- 1 will go on the Xtreme and one on my Phantom.

I suppose it doesn't make any difference on 2.4Ghz as the internal RF noise is hopefully much lower frequencies. Its probably more likely that the receiver would get interference either through the power inputs, or generally through the case as from what I understand the plastic box the receiver is inside, may not be foil lined (no idea as I've not opened mine)

On thing however that could cause problems is the shielding caused by the battery, I suspect it would cast a considerable RF shadow at 2.4GHz, so I'd prefer to have the antenna below the main body of the aircraft where there is clear air between them and the TX.

I third (or fourth) the suggestion to look at the other thread. I made my own profile after downloading and looking at the Ianwood profile. Big difference was that I put it all on an F550 and there are additional tweaks needed. I put the gimbal on the dial, had to correct Failsafe (apparently just a thing with non-Phantom NAZA), and some other things. I still use my stock Tx on the P2. One reason is that I want to put both in the air at once for a short video I'm planning. Also, the guys over on the Immersion/Spironet thread are getting huge distances with just the stock Tx on the P2.

... Also, the guys over on the Immersion/Spironet thread are getting huge distances with just the stock Tx on the P2.

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I hear (and saw) that. Hence why I kept my stock receiver intact, and the radio is well cared for and stowed.

My reasons for changing the receiver, and playing around is mainly for R&D and self study- I am slowly becoming accustomed and comfortable with tearing these things down, and rebuilding or modifying various things... I am using the Phantom as a test bench to get back into r/c (not my original intentions) and to learn basics on quad rotors, which will provide the foundation for multi rotors in general.

I am wanting to add switched channels which the stock receiver and Naza will not handle- therefore an aftermarket receiver with more diverse options, and tweaking the radio to affect those options is more what I am after.

I stopped turning wrenches on the sled years ago- too old and too sore from the injuries- but I will not pay somebody to turn wrenches on something so serious as several grand worth of technology in the air- if there is a problem, I want the mea culpas all right here as I am very serious about the safety aspects of this hobby. I spent years before finding a mechanic I could trust my motorcycle to- that **** is life and death but pretty much I suffer the consequences if there is some slack... the levity of flying even a small UAV and the potential for harm involves other people's lives and careers in such a way I have to be able to sleep at night.

I spoke with my wife- I want to teach her how to operate a camera and gimbal via remote- I am all about the flying, and building- we are going to do this hobby together, but the tech falls on me and when I consider the Phantom, I realize it was the perfect choice to do this.

One day, the stock Rx and Tx will be reunited, and I will set it on a shelf... or not. I may just do insane things like find massive honking motors and tear the camera gear off, set up a bounce cushion on the bottom for belly landings, and fly it's **** rotors off.

I loaded the Ian Wood profile on the F8G last night and took the P2 for a test flight at sunrise (before the wind blew up).

As Roger points out, the Ian Wood profile has a lot of nice extra features -- a dual rate switch, better gimbal control, and a timer that starts when the throttle is activated. The GPS-ATTI-MAN/ATTI/FS and the OFF-HL-CL switches are also better positioned than in the Aerial Pixels profile which reverses the switch positions and uses the large inner switches instead of the smaller outside switches. I've gotten used to flipping to ATTI and HL without looking at the Stock TX, and found myself flipping null switches with the Aerial Pixels profile.

Kudos to Ian Wood for sharing his work with such clear instructions and illustration.

I am getting some unwanted yaw (the P2 is self-rotating 45-90 degrees at random intervals) since changing profiles, but presumably a recalibration will remedy that.

As for the possibility of an inadvertent throttle cutoff with an unmodified 8FG joystick mentioned above, the spring return kit was literally in my mailbox two days after I e-mailed Futaba support. The part number is 6528769.

Other than removing the back cover of the 8FG, nothing else has to be disassembled to install the return spring. There are no instructions, so it IS necessary to study the right hand stick mechanism carefully to understand how the rocker arm, bracket and spring are installed, then it takes about 5 minutes and a good pair of tweezers to put it together.

Once installed, as soon as you release the 8FG throttle, it jumps back to the center position exactly like the stock DJI TX. You can completely remove the ratchet, or, just loosen it so there is a very slight detent, which I prefer.

I'm about half way through building an F550, so some kind of third party TX is inevitable, sooner or later. After watching six or seven fly away videos on You Tube -- especially the Phantom that took off on its own in LA, bounced off power lines and travelled through three or four neighborhoods at rooftop level, barely clearing buildings and highway bridges -- I decided that sooner might be better.